A Shaft Vibration Monitoring Method of Asymmetric Combined Cycle Unit Based on Finite Element Theory

Abstract

The invention discloses an unsymmetrical combined cycle unit shafting vibration monitoring method based on the finite element theory. The unsymmetrical combined cycle unit shafting vibration monitoring method based on the finite element theory comprises the following steps: obtaining a finite element model through the three-dimensional modeling and the finite element mesh division of the unsymmetrical combined cycle unit shafting; obtaining a displacement response in the direction of two main inertia axes at each bearing position by applying boundary conditions to perform unbalanced response calculation; changing the elevation and stiffness of n (n = 1, 2,...,8) bearings at the same time successively in the change range of the common bearing elevation and stiffness to obtain the unbalance response at the 8 bearings; recording to obtain the response of each bearing with the changes of the bearing elevation and stiffness of a certain n bearings; and performing experimental determination on the unsymmetrical combined cycle unit shafting and arranging sensors for vibration monitoring. In the process of the experiment, the cause of the vibration response change can be obtained through detecting the vibration changing law of each bearing and finding the corresponding working conditions in the database, so that the vibration monitoring of the unsymmetrical combined cycle unit shafting is realized.

Description

Technical field: [0001] The invention relates to a vibration monitoring method for shafting of an asymmetric combined cycle unit based on finite element theory. Background technique: [0002] Since the end of the 20th century, power generation technology has become increasingly mature, major changes have taken place in the structure of energy resources around the world, and people's requirements for environmental protection have also increased. The obvious advantages such as short length, small footprint, and minimal environmental pollution have become more and more important in the power system, and gradually replacing coal-fired heating units has become the main development trend. [0003] In the construction process of major thermoelectric centers, asymmetric air-cooled generator rotors are gradually applied to the shafting of combined cycle units. The section stiffness of the generator rotor adopts an asymmetric form, the rotor body is cylindrical, and the surface is mi...

AI Technical Summary

Problems solved by technology

Due to the asymmetric rigidity of the section of the generator, the static deflection of the rotor will be different when the rotor rotates to different angles, and the difference in deflection directly leads to the different dynamic stiffness at different angles, which leads to the phase vibration of the shaft system of the asymmetric combined cycle unit. Compared with the fully symmetrical shafting vibration, different characteristics appear, which brings great difficulties to the shafting vibration monitoring of asymmetric combined cycle units

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